This invention relates to a magnetic recording and playback apparatus and a magnetic recording and playback method, and more particularly to a magnetic recording and playback apparatus and a magnetic recording and playback method which can be applied to a tape streamer for backing up data of a server or the like.
Conventionally, tape streamers are divided into two types including a one-reel type and a two-reel type. In tape streamers of both types, a title of a magnetic tape, file names recorded on the magnetic tape and other information are recorded at the top of the magnetic tape, and the data recorded in the top area of the magnetic tape are used as management data to allow accessing to a physical volume recorded following the top area. Further, in the tape streamers, a logical volume is defined in an area defined by the physical volume, and a user area is set in the logical volume.
Therefore, in a tape streamer which employs such a format as just described, if desired data are recorded onto a magnetic tape, then the magnetic tape is rewound and the management data recorded in the top area of the physical volume are updated. Further, after the magnetic tape is loaded into the tape streamer, the tape streamer first accesses the top area of the magnetic tape to acquire its management data.
It is considered that a conventional tape streamer of the two-reel type can reduce the time required for loading and unloading of a magnetic tape if an IC tag is adhered to the tape cassette and management data recorded at the top of the magnetic tape are recorded into the IC tag.
In particular, in the tape streamer having the configuration just described, if management data are recorded not into the top area of the magnetic tape but into the IC tag upon unloading of the magnetic tape, then it is possible to feed the magnetic tape to the nearer side of the top and the tail of the magnetic tape to unload the magnetic tape. This can reduce the time required for unloading when compared with an ordinary unloading method wherein the magnetic tape is rewound to the top thereof without fail. Further, upon subsequent loading, if the management data recorded in the IC tag are read out, then the user area of the magnetic tape can be accessed even if the magnetic tape is not rewound to the top thereof. Consequently, the time required for loading can be reduced. Further, if free time or the like is made most of to update the management data recorded in the top area of the magnetic tape so as to correspond to the management data recorded in the IC tag, then the magnetic tape can be accessed correctly also by another tape streamer which is not ready for the use of such an IC tag as described above.
Such IC tags as described above are divided into two types including a non-contact type and a contact type. An IC tag of the contact type, however, has a drawback in that soiling to terminals of the IC tag or the like sometimes disables reading out of information recorded in the IC tag. Further, where the IC tag is transported from a storage place thereof by a transport apparatus and automatically loaded into a tape streamer, it is difficult to read out information recorded in the IC tag during the storage or the transportation. Therefore, the IC tag of the contact type has another drawback in that the information recorded on the magnetic tape cannot be acquired if the tape cassette is not loaded actually into a tape streamer. In contrast, where an IC tag of the non-contact type is used, deterioration of the reliability originating from soiling to terminals or the like can be eliminated effectively. Further, if a reader-writer is placed on a rack, a transport apparatus or the like, then such an operation as to confirm a tape cassette to be loaded into a tape streamer before it is loaded actually can be carried out.
However, most of application programs for driving a tape streamer are so designed as to record data of an identification code of a magnetic tape and so forth into the top area of the user area of the magnetic tape and then access the data of the identification code and so forth when accessing to the user area is started. Therefore, also where such an IC tag as described above is utilized, in order to actually start accessing to the magnetic tape when the magnetic tape is loaded, it is necessary to rewind the magnetic tape to the top thereof after all. Therefore, the accessing to the magnetic tape requires time as much.
One of possible solutions to this problem may be to additionally record data of an identification code and so forth relating to such an application program as described above (such data are hereinafter referred to as management data by an application program) into the IC tag. This, however, necessitates modification to the application program so as to be ready for such a change in specifications, and existing application programs cannot be applied as they are. Incidentally, a very high degree of reliability is required for a tape streamer, and it is considered necessary to avoid modification to an application program for backup as far as possible if the application program has exhibited favorable results.
It is an object of the present invention to provide a magnetic recording and playback apparatus and a magnetic recording and playback method which can access a magnetic tape in a significantly reduced time.
In order to attain the object of the present invention, according to an aspect of the present invention, there is provided a magnetic recording and playback apparatus for successively forming slant tracks on a magnetic tape and recording user data onto the slant tracks, comprising means for recording data necessary for accessing to the magnetic tape and part of the user data recorded on the magnetic tape at a predetermined position of the magnetic tape, and means for discharging the magnetic tape.
According to another aspect of the present invention, there is provided a magnetic recording and playback method for successively forming slant tracks on a magnetic tape and recording user data onto the slant tracks, comprising the steps of recording data necessary for accessing to the magnetic tape and part of the user data recorded on the magnetic tape at a predetermined position of the magnetic tape, and discharging the magnetic tape.
In the magnetic recording and playback apparatus and the magnetic recording and playback method, data necessary for accessing to a magnetic tape and part of user data recorded on the magnetic tape are recorded at a predetermined position of the magnetic tape, and the magnetic tape is discharged. Consequently, immediately after the magnetic tape is loaded subsequently, the data necessary for accessing to the magnetic tape can be acquired in a short time, and accessing to the magnetic tape can be started in a shorter time as much. Further, the part of the user data recorded on the magnetic tape can be acquired in the proximity of the position at which the magnetic tape is loaded. Therefore, if the part of the user data are set to data which are required at an initial stage by an application program or to data accessing to which occurs in a comparatively high frequency, then the data can be provided to a host apparatus without feeding and accessing the magnetic tape every time. Consequently, the time required for accessing to the magnetic tape can be reduced significantly when compared with the prior art.
The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements denoted by like reference symbols.